Archery bows are available in a variety of forms. Long bows, recurve bows, compound bows and the like, which are all basically intended to propel an arrow through the transfer of stored energy in the bow through a bow string. A recurve bow may incorporate a rigid handle section to which an opposing pair of flexible limbs are secured in a manner unique to recurve bows and familiar to those in the archery industry. Similarly, a compound bow is provided with a rigid handle portion to which flexible limbs are secured; long bows and similar types of archery bows are usually constructed with the handle and limbs formed in a unitary structure without a discernibly separate handle portion or limbs. Other archery bows are those wherein the limbs are separable from the handle.
Compound bows differ from most bows in that they include wheels or cams attached at the free ends of the limbs to obtain a mechanical advantage in bending the bow. Typically, two eccentrics are used, with lacing wound from an anchor at one end of a first limb to the eccentric at the end of the other limb, to the eccentric at the first end, then back to an anchor at the other end. The middle span between the eccentrics contain the serving or region for receiving the nock of the arrow. Lacing can refer to a single piece bowstring or a three piece line comprising two end cables connected by a central stretch between the wheels which forms the bowstring.
It is well known in the industry that archery bows tend to generate undesirable vibrations and noise during use, which can detract from the performance of the archery bow. During operation the archer nocks an arrow of the bow string and draws his or her bow back to full draw, hoping to shoot the arrow straight and sure to hit a target some distance away. The drawing of the bow to full draw stores kinetic energy in the archery bow and bowstring which, when released, transfers this kinetic energy by a forward thrust to the arrow. When the bowstring is released, most of the stored kinetic energy is transferred to the arrow, causing the arrow to fly according to the force and direction of the bowstring travel. Ideally, all of the stored energy should be transferred to the arrow, but this is not possible due to the physics, mechanics, and dynamics of the bow, bowstring, and arrow system configuration. The energy that is not transferred to the arrow is transferred back into the archery bow and to the archer him/herself. This returned energy appears to the archer as recoil.
This recoil can also cause unwanted vibration and/or noise in the bow. When the bowstring is released, the limbs accelerate forward and engage in a series of rapid vibrations which ultimately die down. This series of vibrations may be so forceful as to affect the flight of the arrow. This can detract from the performance of the bow. Additionally, when hunting, such noise and vibration can cause an animal to move before the arrow strikes the intended target causing misses, or even worse, a wounded animal.
The control of leftover energy which results from the firing of an archery device in the form of vibration and noise has mostly been centered around hydraulic or mechanical dampening devices which were attached to the non-working portion of the bows and which acted independently of the limbs. One known means of controlling recoil forces is disclosed in U.S. Pat. No. 5,362,046 to Sims. The disclosed damper is commercially available and marketed as an archery bow damper, called the “LIMB SAVER”. This device has a mushroom-like configuration provided by a head and an integral stem and is fabricated from a soft elastomeric material. The stem is capable of oscillating over a 360° span in directions generally normal to the longitudinal axis of the device. The peripheral part of the head can oscillate around its circumference in directions generally paralleling that axis. For this vibration damping device to function effectively, it is essential that the ratio between the diameter of the head and length l of the stem be between 5:1 and 1:1.
Noise reduction had also been accomplished by the use of string silencers. However such string silencers did not have an effect on vibration and they reduced projectile velocity.
There are several other patents which are alleged to solve the problem of noise and vibration resulting from the above-described leftover energy resultant from the use of an archery bow. Among those patents are the following U.S. patents:
U.S. Pat. No. 4,893,606 discloses a vibration damper in the form of an internal, flow-limiting structure and high density fluid inertial mass which projected from the handle of the bow.
U.S. Pat. No. 5,016,602 provides a bow stabilizer to reduce recoil, shock and vibration forces and noise. This was in the form of a hollow body which was partially filled with granular solids, and which projected from the handle of the bow.
U.S. Pat. No. 5,016,604 discloses a string silencer for an archery bow in the form of a double-faced fleece polyester fabric.
U.S. Pat. No. 4,080,951 provides an archery bow string silencer in the form of fibrous material secured to a flexible support which was connected to the bow string.
U.S. Pat. No. 4,570,608 discloses an archery bow stabilizer and vibration damper in the form of an energy dissipating rod which was fixed to, and projected from, a stud which was rigidly embedded in the archery bow.
U.S. Pat. No. 5,285,767 provides an archery shock absorption device in the form of a flexible connection, (i.e., an elastomeric member) of selected resilience in the structural path between the handle riser of an archery bow and the sighting element of the archery bow.
U.S. Pat. No. 5,411,009 discloses an apparatus for eliminating noise and vibration in the form of a fluid-filled tube which was mounted horizontally to the bow, body and an energy dissipating rod which was fixed to, and projected from, a stud which was rigidly embedded in the archery bow.
U.S. Pat. No. 5,452,704 discloses a device for dampening bowstring vibration in the form of arms normally sprung to a closed position, the arms being faced with cushioning material to embrace the undrawn bowstring.
Finally, U.S. Pat. No. 5,517,979 relates to a shock absorber device for a bow mounted on the bow. The device included a mount which was movable by expansion or compression of a spring in response to the shock generated by the bow.
However, devices and/or methods have proven to be only marginally effective because they cover an insufficient part of the surface area of the archery bow. Additionally, they detract from the performance of the bow by virtue of a reduction of arrow speed. Accordingly, an improved method for dampening shock, vibration and/or noise in compound bows is desirable.